In article , anon
writes

The growbag claims to have no chemical additives, but what does that mean?
If the raw material is creosote treated wood chips, maybe they can get away
with saying they haven't added any chemicals.
I agree with Stephen Howard that it is most unlikely that B&Q would sell
growbags as organic if they contain creosote treated wood chips, because
creosote is banned for use in organic horticulture.

All substances can have a chemical analysis denoting the elements they
contain, but 'chemical' in the context of organic gardening means
manufactured or processed fertilisers, insecticides, herbicides,
fungicides and the like. Organic growbags should contain none of those.
--
Alan & Joan Gould - North Lincs.